Fused Deposition Modeling (FDM) can develop rapid prototype parts or functional models from a thermoplastic material such as ABS (acrylonitrile butadiene styrene) and polycarbonate. FDM utilizes a computer numeric controlled (CNC) extruder-head that squeezes a fine filament of melted thermoplastic through a modeler nozzle. The controller, operating in accord with pre-select, known variables, activates the modeler nozzle to deposit heated plastic layer-by-layer to form the desired geometric shape. In some instances where select features of the part are left unsupported as a result of the part's orientation, the FDM-based machine may incorporate the use of a second nozzle for extruding therethrough support material to create support structures for any cantilevered portions of the part. In cases where the part's build comprises small, intricate features, a water soluble support material may be used to further facilitate or ease removal from the part's build upon completion. Once the appropriate supporting layer is built, thermoplastic, as discussed above, is extruded through the modeler nozzle to form the part's build. Once the part has finished its successive layers and the build is complete, the part is removed from the FDM-based machine for inspection and final surface preparation, which may include removal of any support material, additional machining, and/or application of a finish coating material.
In instances where a water soluble support material is used, the art offers a range of techniques for removing the support material from the rapid prototype part. One such technique may simply involve immersing the part in a suitable solvent repeatedly via manual or automated means and manually removing the support material using a brush or a pointed tool. Another technique commonly employed in the art may involve placement within a conventional immersion parts washer of the type generally designed to remove grease, carbon, resins, tar, and other unwanted petroleum-based residuals from automotive parts and machine shop equipment. Typically, the conventional immersion parts washer of this type may comprise operable features of ultrasonics to facilitate the cleansing action of the solvent. Although the operable feature noted above may or may not adequately address the removal of support material, the conventional immersion parts washer can be costly in terms of purchase, maintenance and operation, particularly for this limited purpose, and inappropriate in a variety of environmental settings. Given that most machinery having rapid prototype part making capabilities is operated from within an office setting or a similarly suited environment, the coinciding use of a conventional immersion parts washer makes it unacceptable and inappropriate in maintaining a sound, clean environment. Further, some conventional immersion parts washer may expose one to unacceptable health risks, particularly those having ultrasonic capabilities (see World Health Organization Report on Ultrasound and Ultrasonic Noise, Geneva 1982).
Accordingly, there remains a need for a dedicated apparatus capable of removing water soluble support material from a rapid prototype part and operating side-by-side with a rapid prototype part making machine commonly placed and operated in an office setting or a similarly suited environment.